#include <cstdio>
#include <vector>
#define NMax 100000
using namespace std;

vector<int> a[NMax+1];
char deja[NMax+1];

void DFS(int x)
{
    deja[x] = 1;
    for(int i = 0; i < a[x].size(); ++i)
    if( !deja[ a[x][i] ] ) DFS(a[x][i]);
}

int main(){
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);

    int i,N,M,x,y,res=0;

    scanf("%d %d",&N,&M);
    for(i = 1; i <= M; ++i)
    {
        scanf("%d %d",&x,&y);
        a[x].push_back(y);
        a[y].push_back(x);
    }

    for(i = 1; i <= N; ++i)
    if( !deja[i] ) DFS(i), ++res;

    printf("%d\n",res);


return 0;
}